Si cruzamos dos individuos homocigotos de cobaya, uno negro y otro blanco, y sabemos que el carácter negro es dominante sobre el blanco. Su descendencia tendrá la siguiente características

The offspring will be black because they are heterozygous for a dominant trait that is controlled by monogenic inheritance.

Explanation:

Guinea pigs will be heterozygous because they inherit a dominant allele that encodes for the black color and a recessive allele associated with the white color. Heterozygosity is a genetic condition associated with the presence of two alleles at a locus which are inherited from both parents, one from the mother and the other from the father